The present invention relates broadly to exercise machines and, more particularly to an exercise machine wherein the user kneels to operate a weightlifting system to exercise the muscles of the lower back, particularly the spinae erector group.
Typical exercise machines include a frame supporting some form of body support, a set of moveable weights and a system to allow the user to move the weights. Currently, most exercise machines are particularly configured to exercise specific muscle groups. The present invention is directed to a specialized exercise machine for exercising the lower back muscle group. Prior lower back exercise machines typically provide a seat for supporting the user in a seated position providing access to a lever which is operated by the user leaning backwardly to lift the weights. The seated position offers little support against movement of the body and thereby does not effectively isolate the muscles of the lower back. An example of this machine is disclosed in Jones, U.S. Pat. No. 4,500,089.
As a consequence of not thoroughly isolating the lower back muscles, the current machines do not exercise the lower back muscles isotonicly but rather provide an isometric exercise. With isometric exercise, opposing muscles are so contracted that there is little shortening of the muscle tissue but an increase in the tone of the muscles. An isotonic exercise provides muscle contraction in the absence of significant resistance, with a mark shortening of muscle fibers and without a significant increase in muscle tone. Current machines maintain relaxation of the back, trunk and pelvis to stabilize the back and move at the hip joint providing only isometric exercise. Therefore, the muscles of the lower back are exercised only secondarily.
Currently, there is a need for a machine to properly isolate the lower back to primarily exercise the spinae erector group in an isotonic manner.